Discrete element method evaluation of granular crushing under direct shear test conditions

Granular materials forming part of civil engineering structures are subjected to both static and dynamic loads. As a result of these loads, particle crushing occurs. This study focuses on the evolution of crushing in a simulated granular material subjected to a direct shear test. It was found that the discrete element method (DEM) can be used to visualize and understand the evolution of crushing experienced by a granular material during this test. Even though DEM does not normally consider particle breakage, it is possible to simulate crushing by replacing one particle that has failed in tension with a combination of many particles of different sizes. One simulation indicated that crushing did not develop uniformly throughout the sample, and the sample tended to achieve a fractal distribution of particle sizes. The changes in other properties of the simulated granular material such as porosity and shear strength were also recorded, analyzed, and compared to the changes produced during another simulation where crushing was not a predominant feature.